1. Field of the Invention
The present invention relates to rotating holders and carbide cutters used thereon.
2. Description of the Prior Art
Various carbide cutter blades have been utilized in the past, but generally speaking spot facers and boring heads have had carbide bits "sweated" or in some way solidly affixed to the cutter face in a permanent manner, so that the cutter blades are not replaceable. Replaceable cutter blades have been utilized in various types of cutters, and for example U.S. Pat. No. 1,960,319 shows an expansion reamer which has blades that extend radially out from the reamer head. These blades are held in place with tapered head screws that clamp the sides of slots down against the reamer blades.
U.S. Pat. No. 1,791,205 also shows an expansion type reamer that had radially extending blades, which are held in slots through the use of a ring that will expand when a tapered head screw is tightened down into a split in the ring.
U.S. Pat. No. 1,688,558 shows the use of tapered screws to adjust the diameter of a hollow mill, and U.S. Pat. No. 2,092,984 shows the use of a tapered screw head to tighten cutter elements into position for use as well.
Another locking arrangement for cutter blade inserts is shown in U.S. Pat. No. 3,798,724 where again radially extending blades are latched in place through a tooth arrangement. A locking screw is utilized to keep the blades engaged in position.
U.S. Pat. No. 3,711,216 shows a tool bit adjusting device that includes cutter blades that are made of carbide material, and have three sides (they are triangular) each of which can form a cutting edge, and which are held in place with a tightening screw and wedge. In this case the wedge has a groove that engages a portion of the screw head so that as the screw is tightened in, the wedge is pulled into position.
U.S. Pat. No. 1,484,207 illustrates an adjustable cylinder reamer that has a central tapered screw and can be tightened to position to radially adjust cutter blades, and the cutter blades extend out from the cylindrical sides of the head. Adjustable reamers are shown generally as well in U.S. Pat. Nos. 1,474,369; 1,448,273; and 1,074,820.
U.S. Pat. No. 3,591,305 illustrates a reamer that has a replaceable cutting blade that protrudes to one side only, and it is adjustable using a clamping screw arrangement. The amount of protrusion of the blade is also controlled by a wedge shaped member driven by a screw.
U.S. Pat. No. 2,712,686 illustrates an adjustable cutting tool construction having a central screw that adjusts the radial extension of angled blades, that is blades which extend radially outwardly but at an angle with respect to a radial plane.
A cutter which has replaceable blades held in place with a threaded wedge type screw or locking members is shown in U.S. Pat. No. 2,128,571, and a milling saw having two teeth that can be inserted and adjusted as to protrusion by threaded members is shown in U.S. Pat. No. 867,275.
U.S. Pat. No. 3,791,429 shows a rotary cutter which again includes radially extending blades that can be clamped in place and which are replaceable.
The above prior art does show central members that determine the diameter of the cutting blade, and adjusting the size of reamers by using tapered head screws that will control the diameter of the cut as shown. Use of a spot facer or boring head that has a cutting blade that can be inserted into a slot in the head against a pilot member, so that the blade extends outwardly from the head of the cutter, and which are easily replaced, securely held, and backed with gussets or backing lips or flanges are not shown in the prior art.